The present invention relates generally to seat restraint systems for vehicles and, more particularly, to a tension sensing switch assembly for a seat restraint system in a vehicle.
It is known to provide a seat restraint system such as a seat belt in a vehicle to restrain an occupant in a seat of the vehicle. In some vehicles, the seat restraint system may be a lap belt, a shoulder belt or both. Typically, the lap belt and shoulder belt are connected together at one end. The seat restraint system includes a latch plate at the connected end. The seat restraint system also includes a buckle connected at one end by webbing or the like to vehicle structure. The buckle receives the latch plate to be buckled together. When the buckle and latch plate are buckled together, the seat restraint system restrains movement of the occupant to help protect the occupant during a collision.
Some inflatable restraint systems want input information as to the occupancy of the vehicle seat. Deployment of the inflatable restraint may partially depend on information supplied by sensors in the seat such as for determining weight of an object in the seat. When a child seat is placed in the seat and cinched down, the sensors may need a way to distinguish between a large mass and a child seat. Typically, when a child seat is used, there will be high tension in the seat restraint system. Comfort studies have shown that typically a human occupant would not wear their seat restraint that tightly. Readings on seat restraint tension can help to decide the deployment characteristics of the inflatable restraint.
Thus, it may be desirable under certain conditions to provide a switch for sensing tension in a seat restraint system of a vehicle. It may also be desirable to provide a switch for a seat restraint system in a vehicle that allows a control module to help to determine the difference between either a child seat or an occupant. It may be further desirable to provide a switch for a seat restraint system in a vehicle that provides information used to help determine inflatable restraint deployment levels.
It is, therefore, one object of the present invention to provide a switch assembly for sensing tension in a seat restraint system of a vehicle.
It is another object of the present invention to provide a dual resistance switch for sensing tension in a seat restraint system of a vehicle.
It is yet another object of the present invention to provide a dual resistance switch mounted to a seat restraint buckle for sensing tension in a seat restraint system of a vehicle.
To achieve the foregoing objects, the present invention is a tension sensing switch assembly for a seat restraint system in a vehicle including a housing for mounting to a seat restraint buckle of the seat restraint system. The tension sensing switch assembly also includes an actuating member disposed in the housing for movement therein and cooperating with belt webbing and a spring disposed in the housing for cooperating with the actuating member. The tension sensing switch assembly further includes a switch disposed in the housing and cooperable with the actuating member to indicate a first tension level and a second tension level in the seat restraint system when the spring is deflected.
One advantage of the present invention is that a tension sensing switch assembly is provided for a seat restraint system in a vehicle. Another advantage of the present invention is that the tension sensing switch assembly senses tension in the seat restraint system to help identify what is occupying the seat, either a child, child seat or low mass adult. Yet another advantage of the present invention is that the tension sensing switch assembly has a dual resistance switch that is diagnosable. Still another advantage of the present invention is that the tension sensing switch assembly provides information useful in helping to determine deployment of an inflatable restraint system. A further advantage of the present invention is that the tension sensing switch assembly is mounted to a seat restraint buckle of the seat restraint system.
Other objects, features and advantages of the present invention will be readily appreciated, as the same becomes better understood, after reading the subsequent description taken in conjunction with the accompanying drawings.